Knee brace and method for securing the same

ABSTRACT

A knee brace divided into anterior and posterior halves including a proximal member and a distal member. The brace further including at least one substantially inelastic cross strap adjustable in length and connected to the proximal and distal members. The at least one cross strap has first and second portions which intersect at an intersection point located between the proximal and distal members. The intersection point is defined at a location posterior of the frontal plane of the brace.

This application claims the benefit of U.S. Provisional Application Nos.60/637,754 filed 22 Dec. 2004, 60/684,163 filed 25 May 2005, and60/739,407 filed 25 Nov. 2005.

BACKGROUND

A. Background Information on Knee Braces

Knee braces are widely used to treat a variety of knee infirmities. Suchbraces may be configured to impart forces or leverage on the limbssurrounding the knee joint in order to relieve compressive forces withina portion of the knee joint, or to reduce the load on that portion ofthe knee. Moreover, in the event that knee ligaments are weak andinfirm, a knee brace may stabilize, protect, support, or rehabilitatethe knee.

The knee is acknowledged as one of the weakest joints in the body, andserves as the articulating joint between the thigh and calf musclegroups. The knee is held together primarily by small but powerfulligaments. Knee instability arising out of cartilage damage, ligamentstrain and other causes is relatively commonplace since the knee jointis subjected to significant loads during the course of almost any kindof physical activity requiring the use of the legs.

A healthy knee has an even distribution of pressure in both the medialand lateral compartments of the knee. It is normal for a person with ahealthy knee to place a varus moment on the knee when standing so thatthe pressure between the medial and lateral compartments is uneven butstill natural.

One type of knee infirmity that many individuals are prone to having iscompartmental osteoarthritis. Compartmental osteoarthritis may arisewhen there is a persistent uneven distribution of pressure in one of themedial and lateral compartments of the knee. Compartmentalosteoarthritis can be caused by injury, obesity, misalignment of theknee, or simply due to aging of the knee.

A major problem resulting from osteoarthritis of the knee is that thesmooth cartilage lining the inside of the knee wears away. This leads toa narrowing of the joint space with the development of cysts anderosions in the bone ends. Because of the narrowing of the joint, bonecomes directly in contact with bone, and an uneven distribution ofpressure develops across the knee which may result in the formation ofbone spurs around the joint. All of these changes ultimately lead toincreasing pain and stiffness of the joint.

While there are no cures to osteoarthritis, there are many treatments.Individuals who have a diagnosis of isolated medial compartmentalosteoarthritis of the knee are confronted with a variety of treatmentoptions such as medications, surgery, and nonsurgical interventions.Nonsurgical interventions include the use of canes, lateral shoe wedges,and knee bracing.

Knee bracing is useful to provide compartment pain relief by reducingthe load on the compartment through the application of an opposingexternal valgus or varus moment about the knee joint. Unloading kneebraces have been shown to significantly reduce osteoarthritis knee painwhile improving knee function.

B. Prior Art Knee Braces

There are many known unloading knee braces. An example of a known braceis described in U.S. Pat. No. 5,277,698 assigned to Generation IIOrthotics, Inc. of British Columbia, which is incorporated herein byreference. Typically, braces of this type are designed to apply a momentabout the knee through two mechanisms. The first mechanism is throughthe angulations of hinge components which induce a bending moment at ahinge. The second mechanism is provided by a three-point bending systemvia a force strap that spirals around the knee and applies a force to aprescribed aspect of the knee.

FIGS. 1 and 2 exemplify the application of forces by the brace on a legand over a knee joint according to U.S. Pat. No. 5,277,698. The arrowsB_(1 and B) ₂ show lateral and force strap forces. The resulting momentsin the leg due to lateral forces are shown by arrows Y_(1 and Y) ₂. Theprincipal force A is that applied immediately adjacent that compartmentof the knee having osteoarthritis. FIG. 2 shows R as the normal axis ofrotation of the knee. The resultant moment Y_(R) is a single rotationalmoment.

It has been found that as the force strap is increased in tension, thehinge valgus producing moment decreases. Therefore, the force strap andthe hinge are found not to be adequately working in harmony. Morespecifically, it was discovered that the hinge produces about 20% of thetotal valgus moment in this brace. It is believed that since the hingeis aligned close to the knee, the strap urges the knee against thehinge. Moreover, the rigidity of this type of hinge limits thedisplacement of the hinge relative to the knee.

In a conventional brace having a hinge, a clearance is provided betweenthe hinge and the knee to allow for movement of the knee towards thehinge. This results in a bulky brace since a large hinge is requiredwhich may extend at least an inch away from the knee.

It has been determined that if more unloading of the knee is required bythe brace than is obtained from normal strap tension, and if the forcestrap is further tightened, the knee is drawn towards the hinge andmight strike the hinge. This results in the hinge applying forces to theknee that counteract the force applied by the force strap. In turn, theadditional tightening of the force strap is mitigated or negated by theforce exerted onto the knee from the hinge.

For example, a study was conducted on a patient wearing a conventionalknee brace having a force strap. In normal strap tension, the forcestrap component unloaded 5.8 Nm of the knee and the hinge unloaded about2.2 Nm. By increasing the force strap tension, the unloading of theforce strap resulted in 11.6 Nm, but the hinge resulted in unloading−2.4 Nm since the hinge was pressed against the knee.

As will be more fully evident in the ensuing discussion, the embodimentsdescribed herein are provided to overcome the deficiencies of prior artunloading braces by including arrangements that provide maximumunloading of the knee brace, while removing the mitigating effects ofthe hinges in known knee braces. Moreover, the embodiments of theinvention are arranged for treating compartmental osteoarthritis, andhave improved mechanical properties that remove undesirable rotationalforces incurred by the brace and provide a more effective mechanism forgenerating a valgus or varus moment at the knee.

While known knee braces are successful at reducing pain at orstabilizing a knee joint, many users find these braces to be bulky,difficult to don, complicated to configure, and uncomfortable to wear.For these reasons, the embodiments described herein have streamlinedfeatures capable of providing relief for medial or lateral compartmentalosteoarthritis, or functional stability of the knee without theattendant drawbacks of known unloading knee braces.

SUMMARY

Embodiments of the present invention are directed to an improved kneebrace and knee bracing method that serve to reduce the effects of eithermedial compartmental or lateral compartmental osteoarthritis.Embodiments of the knee brace and variations of the knee bracing methodreduce the effects of compartmental osteoarthritis by applying multipleforces to the knee on the side remote from the compartment havingosteoarthritis while providing forces on the side of the compartment tomaintain the brace securely on a leg while minimizing rotational forces.

According to one embodiment of the knee brace, proximal and distalbreathable shells are inserted into pockets defined by a sleeve andspacer elements corresponding to the shells. First and second forcestraps are connected to the shells and intersect at an intersectionpoint located between the first and second shells, and posterior thenormal axis of the knee brace. A tightening device is provided for eachforce strap to tension or release tension of the force straps against aleg of a user of the knee brace.

In another embodiment of the knee brace, a proximal frame member and adistal frame member each have inner and outer facing surfaces. Aconnecting element links the frame members. At least one force strap isconnected to the frame members. The at least one force strap has firstand second portions that intersect at an intersection point between theproximal and distal frame members.

In a variation of these embodiments, the at least one force strap isdefined as a single substantially inelastic strap that is connected toand spirals between the frame members. The strap defines a first portionhaving a first end anchored to the proximal member and a remainder ofthe first portion connecting to the distal member. A second portion ofthe strap is connected to the distal member and a second end thereofsecures to the proximal member. The first and second strap portionsintersect at an intersection point between the proximal and distalmembers that is preferably located posterior the normal axis of the kneebrace.

According to yet another embodiment, the knee brace is provided with atleast one breathable spacer element having an inner surface connected toan inner facing surface of at least one of the proximal and distalmembers. The at least one spacer element defines an outer surfaceopposing the inner surface and includes a frictional feature.

In one variation of this spacer element, both the spacer element and thefrictional feature are perforated. According to this variation thespacer element is a textile having a surface with a plurality ofapertures upon which a silicone is coated along the non-aperturedportions thereof. This yields a highly breathable spacer element thatprovides resistance to rotational forces caused by the force straps.Moreover, a spacer element on both proximal and distal portions of theknee brace prevents the proximal and distal portions of the knee bracefrom drawing closer to one another due to the forces applied by theforce straps.

In combination with the force straps and spacer elements, one canachieve more unloading forces than with one force strap withoutincreasing the pressure applied to the knee. This is due to the totalunloading moment that is doubled with two force straps; the same amountof pressure is applied to the knee since there are two pressure points.

Second proximal and distal principal points of force are generated bythe spacer elements secured to the frame members on a second side of theleg at locations above and below, respectively, the first proximal anddistal principal points of force. The spacer elements maintain the kneebrace on a leg and the frame members apart. The spacer elements mayremove the need for a hinge as is used in the prior art braces.

Multiple other embodiments of a knee brace and variations of componentsthereof are discussed more fully in the discussion that follows. Thefeatures of the various embodiments of the knee brace result in a kneebrace that provides not only greater unloading of the knee, but alsoresult in a knee brace that is simpler to use and has a slimmer profilethan conventional knee braces.

Of course, other methods, embodiments, and variations thereof aredescribed in greater detail in the following discussion.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood with regard to the followingdescription, appended claims, and accompanying drawings where:

FIG. 1 is a schematic view of forces applied on a leg using a prior artknee brace;

FIG. 2 illustrates the rotational force applied on a leg by the priorart knee brace of FIG. 1;

FIG. 3 is a perspective view of an embodiment of a knee brace dividedalong anterior-posterior, proximal-distal, and lateral-medial planes;

FIG. 4 is a front elevation view of the embodiment of FIG. 3 dividedalong the lateral-medial and proximal-distal planes;

FIG. 5 is a side elevation view of the embodiment of FIG. 3 dividedalong the anterior-posterior and proximal-distal planes;

FIG. 6 is a top plan view of the embodiment of FIG. 3, divided along theanterior-posterior and lateral-medial planes;

FIG. 7 is a perspective view of an embodiment of a knee brace of theinvention;

FIG. 8 is a front elevation view of the embodiment of FIG. 7;

FIG. 9 is a medial side elevation view of the embodiment of FIG. 7;

FIG. 10 is a lateral side elevation view of the embodiment of FIG. 7;

FIG. 11 is an exploded view of the embodiment of FIG. 7 without asleeve;

FIG. 12 is a schematic view of forces applied on a leg using the braceshown in FIG. 7;

FIG. 13 illustrates the rotational force applied on a leg by the braceof FIG. 7;

FIG. 14 generally illustrates where the force is applied externally ofthe knee in the brace of FIG. 7;

FIG. 15 is a sectional view taken along line XV—XV of FIG. 14;

FIGS. 11 and 12 are perspective views of a variation of the force strapand the stability strap, respectively;

FIG. 18 is a detailed perspective view of the proximal shell of FIG. 11;

FIG. 19 is a detailed perspective view of the distal shell of FIG. 11;

FIG. 20 is a detailed sectional view of cut-away XX—XX in FIG. 11;

FIG. 21 is a detailed section view of FIG. 20 generally rotated about180°;

FIG. 22 is a front elevational view of another variation of a proximalshell;

FIG. 23 is a front elevational view of another variation of a distalshell;

FIGS. 24–27 are force diagrams showing pressure distribution acrossprior art frame members and the proximal shell of the brace in FIG. 7;

FIG. 28 is a frontal perspective view of the sleeve of FIG. 7;

FIG. 29 is a rear perspective view of the sleeve of FIG. 7;

FIG. 30 is a front elevational view of a sleeve embodiment for the kneebrace;

FIG. 31 is a perspective view of a feature of the sleeve of FIG. 30;

FIG. 32 is a sectional view taken along line XXXII—XXXII of FIG. 11;

FIG. 33 is a perspective view of a variation of a tightening device onan embodiment of the knee brace;

FIG. 34 is a plan view of the tightening device according to FIG. 33;

FIG. 35 is a schematic plan view of the tightening device according toFIG. 33;

FIG. 36 is a perspective view of another variation of a tighteningdevice on an embodiment of the knee brace;

FIG. 37 is a perspective view of yet another variation of a tighteningdevice;

FIG. 38 is an elevational view of the tightening device of FIG. 37;

FIG. 39 is a rear elevational view of the tightening device of FIG. 37;

FIG. 40 is a front elevational view of the tightening device of FIG. 37;

FIG. 41 is a perspective view of a variation of the base of thetightening device of FIG. 37;

FIG. 42 is a top plan view of the base in FIG. 41;

FIG. 43 is an elevational view of the base in FIG. 41;

FIG. 44 is perspective view of another variation of a tightening deviceincluding the base in FIG. 41;

FIG. 45 is a perspective view of the tightening device according to FIG.44 secured onto the shell of FIG. 22;

FIG. 46 is a elevational view of another variation of a tighteningdevice;

FIG. 47 is a top plan view of the tightening device according to FIG.46;

FIG. 48 is a bottom plan view of the tightening device according to FIG.46;

FIG. 49 is a perspective view of yet another variation of a tighteningdevice in an embodiment of the knee brace;

FIGS. 50–52 show an embodiment of a strap attachment piece;

FIGS. 53–55 are perspective views of a variation of a buckle assembly ofthe knee brace;

FIG. 56 is top plan view of another variation of a buckle assembly;

FIG. 57 is a bottom plan view of FIG. 56;

FIG. 58 is perspective view of the buckle assembly of FIG. 56;

FIG. 59 is a perspective view of another variation of a buckle assembly;

FIG. 60 is a schematic perspective view of another embodiment of theknee brace;

FIG. 61 is an elevational view of a variation of a hinge for the kneebrace;

FIG. 62 is an elevational view of another variation of a hinge;

FIG. 63 is a perspective view of another embodiment of the knee brace;and

FIG. 64 is a perspective view of another embodiment of the knee brace.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

A. Overview

A better understanding of different embodiments of the invention may behad from the following description read in conjunction with theaccompanying drawings in which like reference characters refer to likeelements.

While the disclosure is susceptible to various modifications andalternative constructions, certain illustrative embodiments are shown inthe drawings and will be described below in detail. It should beunderstood, however, that there is no intention to limit the disclosureto the specific embodiments disclosed, but on the contrary, theintention is to cover all modifications, alternative constructions,combinations, and equivalents falling within the spirit and scope of thedisclosure and defined by the appended claims.

It will be understood that, unless a term is expressly defined in thispatent to possess a described meaning, there is no intent to limit themeaning of such term, either expressly or indirectly, beyond its plainor ordinary meaning.

Any element in a claim that does not explicitly state “means for”performing a specified function, or “step for” performing a specificfunction, is not to be interpreted as a “means” or “step” clause asspecified in 35 U.S.C. § 112, paragraph 6.

B. Environment and Context of Embodiments

Numerous embodiments of the invention are provided to reduce the effectof osteoarthritis in a knee joint, or stabilize a knee joint that hasbeen weakened by injury or other infirmities. Embodiments of theinvention may be configured to reduce or cure both medial and lateralknee joint infirmities.

Embodiments of the invention are particularly adapted for a human kneejoint, and may be dimensioned to accommodate different types, shapes andsizes of human joints and appendages. In addition, embodiments may bemodified to orient principal forces exerted by strap systems of theembodiments at any desirable location to treat knee infirmities.

For explanatory purposes, each knee brace embodiment described herein isdivided into sections which are denoted by general anatomical terms forthe human body. Each of these terms is used in reference to a human legwhich is divided in similar sections with a proximal-distal planegenerally extending along the meniscus of the knee between the femur andtibia.

In reference to FIG. 3, an embodiment of the knee brace is divided intoanterior and posterior sections by an anterior-posterior plane. Theanterior-posterior plane generally corresponds to the coronal or frontalplane of a human leg. Each of the anterior and posterior sections isfurther divided about the center of the knee by a tramsvers orproximal-distal planes and median, sagittal or lateral-medial plane.

Referring specifically to FIGS. 4–6, the anterior section of the kneebrace of FIG. 3 has the following quadrants: (I) proximal-medial, (II)distal-medial, (III) distal-lateral, and (IV) proximal-lateral. Theposterior section of the knee brace of FIG. 3 has the followingquadrants: (V) proximal-medial, (VI) distal-medial, (VII)distal-lateral, and (VIII) proximal-lateral.

The anatomical terms described herein are not intended to detract fromthe normal understanding of such terms as readily understood by one ofordinary skill in the art of orthotics.

C. Various Embodiments of the Knee Brace

i. Overview of Knee Brace Embodiments

Referring to FIGS. 7–10, a knee brace embodiment 10 is shown. While thisknee brace is particularly shown and configured for treating lateralosteoarthritis of the knee, it is understood that the knee brace may beconfigured by reversing the features in order to treat medialosteoarthritis of the knee.

According to this embodiment, the brace 10 includes a sleeve 12 coveringor upon which various components and assemblies are secured. As will bedescribed below in reference to proximal and distal frame elements orshells 40, 42, these shells are connected to, inserted into, or securedagainst the sleeve to provide sufficient rigidity to the brace.

According to this embodiment, the sleeve 12 includes a breathablecentral strip portion 14 generally extending along the proximal-distalplane of the brace 10, and a center ring 16 located approximately aboutthe center of the sleeve 12. The center ring 16 is preferablyconstructed from an elastic material so as to provide sufficient flexureof the brace 10 about the center portion thereof, and is located so asto assist a user of the device in placing the center portion over theanterior knee. Moreover, the portion of the sleeve 12 corresponding tothe proximal portion of the knee is left exposed in order preventinterference of extension and flexion of the knee.

First and second force straps 18, 20 are each secured at a first end toa corresponding tightening device 22, 23 that protrudes out of anopening 24, 25 of the sleeve 12. The second end of each of the forcestraps 18, 20 is secured to a corresponding bracket assembly 26, 27 alsosecured to the sleeve 12. The first and second force straps 18, 20intersect at intersection point 21 that is located near or along theproximal-distal plane on the posterior, medial side of the brace 10.

Each of the force straps 18, 20 may include a cushion feature that maybe located near or at locations anterior or posterior of theintersection point 21. Moreover, the force straps 18, 20 preferably eachhave a length adjustment feature 29, such as a hook and loop fastenersystem, to enable adjustment of the length of such straps 18, 20.

In this embodiment, the force straps 18, 20 are substantially inelasticin order to apply a greater amount of pressure against the knee asopposed to what may occur if elastic straps are used. It has been foundthat force straps having substantially elastic properties do noteffectively unload a knee. Instead, elastic force straps pull the kneeinto flexion such that when the leg is straightened, the force strapsresist flexure of the knee. As a result, while tightening the forcestraps may indeed unload the knee, the knee is unable to undergo fullextension due to the tendency of the knee to go into flexion. Unlike theelastic straps, substantially inelastic straps do not possess thesedrawbacks since they draw the knee towards a hinge and unload the kneewhile permitting both flexure and extension of the knee.

It should be understood, however, that embodiments of the knee brace arenot limited to usage of substantially inelastic straps. To the contrary,straps of various degrees of elasticity may be employed with the variouscomponents in different the embodiments of the knee braces to suitvarious needs of an individual wearing the brace.

The first force strap 18 is secured to a lateral-proximal bracketassembly 26 and spirals along the posterior of the brace 10 towards themedial-distal side of the sleeve 12. The first force strap 18 thenenters in the sleeve 12 and secures to a distal tightening device 23generally located on the anterior-lateral, distal side of the sleeve 12.

The second force strap 20 is secured to a lateral-distal bracketassembly 27 and spirals around the posterior of the brace 10 towards themedial proximal side of the sleeve. The strap 20 then enters the sleeve12 and secures to a proximal tightening device 22 generally located onthe anterior-lateral proximal side of the sleeve 10. As will bedescribed in the ensuing discussion, the proximal and distal tighteningassemblies 22, 23 are provided to incrementally tension the first andsecond force straps 18, 20, and selectively allow release of tension inthe force straps 18, 20.

A proximal stability strap 28 is secured to the medial side of the brace10 and extends to the lateral side whereat it is connected to a proximalbuckle assembly 32 that is connected to the sleeve 12. A distalstability strap 30 is secured to the medial side of the sleeve 12 andextends to the lateral side whereat it is connected to a distal buckleassembly 33 which is also connected to the sleeve 12.

According to this embodiment, each of the stability straps 28, 30includes a cushion feature 34, such as foam or a textile pad that issecured thereon for enhanced rotational prevention and additionalcomfort. The stability straps 28, 30 each have an adjustment feature 35,such as a hook and loop fastener system, to enable adjustment of thelength of such straps 28, 30. Moreover, the cushion feature may includea frictional feature (not shown), such as a pattern of depositedsilicone, rubber, or a mildly abrasive material. In addition, thecushion feature may be breathable, and have a construction similar tothe spacer elements described below.

In one variation, the stability straps may be releasably secured to theknee brace. For example, the stability straps may include a snapfastener element that corresponds to a snap fastener element supportedby shells of the knee brace. In another variation, other suitablereleasable fasteners may be used to permit installation and removal ofthe stability straps from the knee brace.

An embodiment of the knee brace may be provided alternatively with oneforce strap connected to a tightening device and another strap that isadjustable with a fastener system such as hook and loop fasteners. Forexample, in the event that it is desired to provide a low profile brace,one could use a force strap system that is connected to and adjustableat the proximal portion (corresponding to the femur of the wearer) ofthe brace that includes a tightening device, whereas the force strapsystem connected to the distal portion (corresponding to the tibia ofthe wearer) may simply use a hook and loop fastener system. Variationsof this embodiment are also useful in order to mitigate issues of atightening device extending over pressure points that may be presentover the tibia.

The embodiment of the brace of FIGS. 7–10 is generally oriented torelieve lateral compartmental osteoarthritis of a left knee. This bracemay be configured to treat medial compartmental osteoarthritis of theleft leg or, in the alternative, medial or lateral compartmentalosteoarthritis of a right knee. The reconfiguration for treating medialcompartmental osteoarthritis comprises arranging the force straps in areverse configuration so the force straps have an intersection point onthe proximal-distal plane on the posterior-medial side of the device.

Turning to FIG. 11, the internal features of the embodiment of the brace10 are shown in greater detail without the sleeve 12. Of interest arethe proximal and distal shells 40, 42 which provide the structure forbrace, and connect to the force straps 18, 20 and the stability straps28, 30. Of additional interest are the proximal and distal spacerelements 46, 48 which provide anti-rotational means, such as africtional feature, and cushioning for the brace 10 when worn on a leg.

The proximal and distal shells 40, 42 are configured for placementbetween the lateral and medial sides of an anterior portion of the brace10. Similarly, the proximal and distal spacer elements 46, 48 areconfigured with a shape generally corresponding to the proximal anddistal shells 40, 42, and are arranged for connection to a rear portionof the sleeve 12 in register with the shells 40, 42. It is desirablethat the proximal and distal shells 40, 42 be in register with theproximal and distal spacer elements 46, 48 so that as the force strapsand stability straps are tensioned about a leg. The spacer elements 46,48 are urged against a leg so as to prevent rotation of the brace 10 dueto the forces applied to the leg from the force straps.

According to variations of the shells, they may be configured forplacement on the posterior side of the brace, or at least have sectionsthat extend over a portion of the posterior section of the brace. Inaddition, variations of the shells may involve one shell such as theproximal shell extending about the anterior side of the brace betweenthe lateral and medial sections, whereas the distal shell extends overthe posterior side of the brace and further includes a segment wrappingover at least one of the lateral and medial sides to cover a portion ofthe distal-anterior section of the brace.

A benefit of the spacer elements in a hingeless knee brace is that thesespacer elements prevent migration of the shells towards one another. Thespacer elements also maintain the knee brace on the user's leg due toanti-rotation means. Moreover, the spacer elements can also resist anyrotational forces that may be applied by the force straps.

ii. Method of Applying the Knee Brace

In operation, the embodiment of the brace according to FIGS. 7–11 isattached to the user, for whom it may be custom made or pre-fabricated,by positioning the device on the leg with the center portion of thesleeve placed over the anterior knee. The proximal and distal forcestraps 18, 20 are positioned above and below a side of the knee, andtightened accordingly. This arrangement of the force straps ensures thatthe force straps tighten above and below the knee as the leg moves intoextension and loosens as the leg moves into flexion. The tightening ofthe force straps 18, 20 during extension of the knee prevents movementof the bone upon extension of the leg, and thus treats the adverseaffect of compartmental osteoarthritis.

FIGS. 12 and 13 illustrate the brace on a left leg 11 that definesproximal and distal portions corresponding to the femur and tibia,respectively. The tightening of the force straps 18, 20 tend todepressurize the compartment of the knee by increasing the space betweenthe bones on the affected side of the knee. The configuration of theforce straps along the frame elements 40, 42 provides reaction pointsfor the force straps 18, 20. Thus, tightening of the force straps 18, 20causes the frame elements 40, 42 in combination with the spacer elementsto stabilize the knee on the side opposite the intersection area 21.

From FIG. 12, the forces A₁ and A₂ are shown applied to the medial sideof the knee at a greater degree than the single force A generated by theprior art braces, as exemplified in FIGS. 1 and 2, due to the greaterdistribution of pressure on the leg. Additional forces B are applied onthe lateral side of the leg approximately where the force straps areattached to the proximal and distal members. By applying two forces,these forces counteract to mitigate the rotational moment that ispresent in the prior art braces wherein rotational forces Y_(R1) andY_(R2) are generally equal to and cancel one another.

It has been found that if only one force strap is used without anyintersecting points, as in the prior art braces, the skin and softmuscle tissue move with the shells. As a result, the unloading effect ofthe straps decreases significantly. By using the two force straps toform forces A₁ and A₂, rotation of the device on the leg is reduced andeffectively prevented. This provides a sufficient unloading effect bythe brace on the knee.

The force straps are substantially inelastic since, as mentionedpreviously, it has been found that in prior art braces that employelastic force straps, the knee and leg counteract the suppleness of theelastic straps thereby reducing the unloading effect on the knee. Byusing substantially inelastic force straps, the knee is unable to resistthe straps and, consequently, a greater unloading effect is obtained ofthe knee.

Referring to FIGS. 14 and 15, the resultant forces A₁ and A₂ are appliedas the knee goes into extension. The force straps preferably cross atintersection point 21 at angle α ranging greater than 0° and at or lessthan 45° posterior of the normal axis of rotation of the knee with theknee cap 51 being in front of rotational axis R and tibia 53. Theintersection point is preferably not the point of unloading; instead,the unloading point is directly on the lateral side for the medialbrace, and directly on the medial side for the lateral brace.

The knee brace may be tailored to optimize the forces generated by theforce straps. When the brace includes two force straps or has a singleforce strap with two intersecting portions, a greater moment is appliedto a leg providing that the same force is now applied by two forcestraps. This results in a lower angle that may be used to configure theforce strap(s), and consequently proximal and distal frame members orshells may be positioned closer together as opposed to in prior artbraces having only a single cross-strap which spirally extends oncebetween proximal and distal members.

In following discussion, descriptions and variations of the specificcomponents pertaining to the inventive knee brace are described.

iii. Straps

The force straps and stability straps may be constructed from a varietyof different textiles and other suitable materials. According to onevariation exemplified in FIGS. 16 and 17, the force strap 400 andstability strap 412 are shown as comprising a two layer system; an innercore 404, 416 surrounded by an outer layer 402, 414. Suitable stitching406, 420 is provided to secure the inner core 404, 416 and outer layer402, 414 together. When viewed from a rear end, the two layer systemcombines to form a C-folded strap wherein the outer layer 402, 414 wrapsaround the inner core 404, 416 to generally define an elongated C-shapeabout the corners of the strap.

The inner core 404, 416 is preferably constructed from a soft loopmaterial. This material is generally soft to the touch so that for aknee brace having the strap extend about the popliteal (back of theknee), the worn strap is comfortable to the wearer of the brace. This isevidenced when the wearer flexes his leg as well as when the leg isfully extended. The compliance and softness of the inner core mitigatesthe need for a cushion feature of the very type shown in FIGS. 7–10.

The outer layer 402, 414 may be constructed from any suitable textilesince the compliance of the strap is essentially provided by the innercore 404, 416. This enables the use of a cosmetically pleasing or asubstantially inelastic material.

Both of the straps 400, 412 may include a tab 410, 418 located at thefront end of the straps to provide adequate reinforcement to this area.The tab 410, 418 may comprise a plastic or metal piece that is securedto the front end of the straps by a press fit, stitching, adhesive orother suitable means. In addition, as will be discussed in furtherdetail below, the force strap 400 may include indicia 408 representativeof incremental settings of the strap.

In yet another variation, the stability straps may be substantiallystretchable and secured to the sleeve or shells. The straps according tothis variation may be configured so that they are dimensioned so as topermit the brace to be donned and doffed by being slidable on a leg ofan individual wearing the brace, but sufficiently tensioned so as towear tightly on the individual's leg.

iv. Shells

FIGS. 18 and 19 illustrate one variation of the proximal and distalshells 40, 42 of the brace of FIG. 7. Each of these shells 40, 42 has aperforated structure 52 which ventilates the brace and thereforemitigates heat build-up when the brace 10 is worn on a leg. Moreover,each shell has a clearance 50 which extends between the lateral andmedial sides thereof as a further ventilation feature. While the shells40, 42 are of sufficient rigidity and strength to withstand forcesexerted by the force straps 18, 20 and the stability straps 28, 30, theshells 40, 42 may be flexible to conform to corresponding portions of aleg.

Because the shells 40, 42 have a perforated structure 52 and theclearance 50, the shells may be sized larger than other known structuralfeatures or frame members known in the knee bracing art. For example,the proximal shell 40 has an enlarged first side portion 54 thatprovides sufficient support against a leg and can accommodate thetightening device 22 and buckle assembly 26. The shell 40 also defines aprotruding section 56 extending from the first side portion 54 in adirection generally tracing the path of the second force strap 20 so asto distribute the pressure of the strap against the leg.

The shell 40 defines a second portion 58 that is sufficiently large tosecure to a leg, yet is of minimal size to prevent excessive intrusionon a corresponding side of a leg. Similarly, the distal shell 42 definesfeatures corresponding to the proximal shell 40, such as an enlargedfirst side portion 68, a protruding section 70, and a second sideportion 72.

As exemplified in FIGS. 20 and 21, each of the shells 40, 42 preferablyhas provisions for mounting the tightening devices 22, 23, the bracketassemblies 26, 27, and the buckle assemblies 32, 33. The shells 40, 42may each include an opening 66 for receiving a mounting feature 82 of atightening assembly, and an eyelet 62 located on the lateral portions54, 68 which is arranged to receive corresponding pins or similarfeatures 82 of the bracket assemblies 26, 27 and buckle assemblies 32,33. The eyelet 62 defines a seat portion 64 in which the mountingfeature 82 of the bracket and buckle assemblies, such as a pin, button,flange, hook, or similar element, are urged and retained there against.The seat portion 64 is defined as a reduced portion of the eyelet 62having a radius just larger than the mounting feature.

The construction of the eyelet of this embodiment is particularlyadvantageous in that it facilitates detachment of the buckle assembliesand bracket assemblies from the device when not worn on a leg. Forexample, when the force straps and stability straps are detensioned, orthe brace 10 is not worn, the mounting feature 82 may be urged from theseat 64, and subsequently removed from the shells 40, 42. However, whenthe straps are in tension, the mounting feature is urged and locked inregister with the eyelet seat 64.

In a variation of this embodiment, individual eyelets of the typedescribed above may be defined on the shells for individuallyaccommodating both a buckle assembly, and a bracket element having amounting feature. According to another variation of this embodiment,either of the buckle assembly or bracket element may have a hook whichis securable against a corresponding eyelet defined in the shells. Inyet another variation of this embodiment, the bracket element and buckleassembly may be permanently secured onto the shells using means such asrivets or other known fasteners.

In accordance with another variation of the shells, FIGS. 22 and 23 showproximal and distal shells 422, 448 having a different perforatedstructure 424 from the embodiments of FIGS. 18 and 19. Specifically, theperforated structure 424 comprises a plurality of generally horizontalslots 426 extending along segments across the width direction of theshells 422, 448. These slots 426 are interspersed with a plurality ofslats 428. Frame portions 430 of each of the shells 422, 448 surroundthe slots 426 and slats 428.

The shape of the proximal shell 422 generally resembles the shape of theproximal shell shown in FIG. 18. Particularly, the proximal shell 422defines a second side portion 432 that extends downwardly from atransverse portion 434 corresponding to the anterior-proximal portion ofthe shell and spanning to a first side portion 436. The transverseportion 434 includes an arcuate profile that is preferably pronounced onthe distal side thereof and conforms to the anatomy of a thigh. Thefirst side portion 436 extends downwardly beyond the distance extendedby the second side portion 432, and is generally wider in size than thesecond side portion 432 to provide additional support on the leg.

The proximal shell 422 includes an eyelet 440 located on the second sideportion 430. The eyelet 440 is configured for receiving a pin or lockingdevice of a buckle assembly. A seat 442 is located on a side of theeyelet that is preferably distant from the second side portion 432 ofthe shell. The seat 442 may form a slot extending from the eyelet 440and has a smaller diameter than the eyelet 440.

The proximal shell 422 also includes a slot 444 that is separate andlarger than the slots 426, and is located near the transition betweenthe first side portion 436 and the transverse portion 434. Preferably,the slot 444 is directed at an angle relative to the slots 426. The slot444 includes a compliant edge 445 that is located at a side thereofclosest to the transverse portion 435. The complaint edge 445 imparts asmaller effective height for the slot 444 and is arranged for receivinga pin, knob or other securing means carried by the ratchet assembly, asdescribed more fully connection with FIG. 43.

The compliant edge 445 is formed of a material that is preferably moreflexible than the material used to form the proximal and distal shells,422, 448. For the example, the rim 445 may be a silicone rubber or asuitable polymeric material.

The proximal shell 422 also includes a slot 446 that is located at thesecond side portion 432 of the shell. Similarly, the slot 446 is locatedat an angle relative to the slots 426 and likewise includes a compliantedge 447 that is located at an end portion remote from the transverseportion 434.

The shape of the distal shell 448 differs from the shape of the distalshell 42 shown in FIG. 19. Specifically, the distal shell 448 includes asecond side portion 450 that connects to a transverse portion 452corresponding to the anterior-proximal portion of the shell. Thetransverse portion 452 has a proximal arcuate profile 453 that isgenerally contoured to the shape of a shin of a human leg. From thetransverse portion 452, a proximal side of the distal shell rises toapex 455 which provides additional support to the wearer at a first sideportion 454 of the shell 448. The shell 448 also includes a calfextension member 456 that protrudes from the second side portion 454 ofthe shell 448.

The calf extension member 456 extends to the posterior section of thebrace when worn on a leg. The calf extension member 456 has the benefitof preventing the shell 448 from rotating when the knee brace is worn ona leg, and also serves as an additional suspension feature since it ispreferably configured to extend over the thickest point of a human calf.Another benefit of the calf extension member 456 is that it removes thenecessity of two stability straps for connection to the distal shellsince the calf extension member effectively provides substantial supportabout the calf.

The distal shell 448 includes an eyelet 458 that has a seat portion 460which is similarly constructed as the eyelet 440 and seat portion 442 ofFIG. 20. The distal shell also includes a slot 462 and a correspondingcompliant edge 463 that generally corresponds to the same location withthe exception of their orientation as the slot 444 and respective rim445 in FIG. 20. Also, the distal shell has a slot 464 and a respectivecompliant edge 465 that corresponds in location with the exception oforientation to the slot 446 and respective rim 447 in FIG. 20.

The shells 422 and 448 may include a compliant feature 470 disposedabout the entirety or at least portions about their periphery. Thecompliant feature is constructed of a material that is more flexiblethan the material comprising the shell bodies. The compliant feature 470extends beyond the outer perimeter of the shells. The compliant featureis preferably a flexible resilient material that is secured to theshells by bonding, mechanical interlocking or any other suitablearrangement. An example of a method for providing the compliant featureis described in U.S. Pat. No. 5,445,602, incorporated herein byreference.

The shells may be custom sized and contoured to accommodate the leg of awearer of the brace. Also, the shells may be preformed to curve to thecontour of a leg, or curved as a result of the straps and sleevescausing the shells to curve about the leg of a wearer of the brace.While the embodiments described herein assume the shells to besufficiently flexible to accommodate a wearer's leg in both extensionand flexion of the knee, the shells can also be configured to besubstantially rigid as in prior art braces.

The proximal and distal shells of these variations may be constructed ofvariety of materials such as TRIAX (abs/nylon blend), polypropylene,polyethylene, nylon, carbon or glass fiber prepeg with thermosetting orthermoplastic resins, and rigid foam from EVA, platezote orpolyurethane. In another variation, the proximal and distal shells maybe constructed similarly to the orthotic sleeve described in U.S. Pat.No. 6,592,539 assigned to Ossur hf of Reykjavik, Iceland, andincorporated herein by reference.

The perforated structure of the shells enables the shells to be sizedlarger than most frame members used in knee braces. As a result, thepressure exerted against the leg by the force straps can be more evenlydistributed about the leg.

FIGS. 24–27 schematically show how the shells of the aforementionedembodiment of the knee brace are advantageous over those in known kneebraces. FIG. 24 schematically shows a hypothetical horizontal forceF_(a), corresponding to the direction of a force strap, extending from amidpoint of a prior art shell 39. In this arrangement, pressure from theforce F_(a) is evenly distributed across the shell 39 and across leg 13.FIG. 25 shows hypothetical horizontal force F_(b) extending from adistal portion of shell 39. In this arrangement, the force F_(b) exertsgreater pressure across the leg 13 at the bottom of the shell than atthe top of the shell.

FIGS. 26 and 27 more aptly exemplify the actual force exerted by a forcestrap on a proximal shell. FIG. 26 shows a shell 39 in the prior arthaving a small size in order to minimize weight of the brace and thegeneration of heat due to the shell being worn against a leg. Becausethe shell is small, the force strap is secured to a center portion ofthe shell and diagonal force F_(c) creates greater pressure on a lowerportion of the shell across the leg 13 than at the upper portion.

FIG. 27 shows shell 40, wherein due to the ability to provide a largershell, the force strap can be mounted at the upper portion of the shell.This results in diagonal force F_(d) which corresponds to a greaterportion of the shell than the force F_(c), and thereby more evenlydistributes pressure from the force F_(d) over the shell and across theleg 13. By placing the force strap above the middle portion of theshell, one can obtain better distribution of pressure over the shell.

It has been found with known prior art knee braces that when forcestraps are not located at the same positions at both proximal and distalframe members, rotation of the frame members may occur. Since theseframe members have a tendency to be significantly smaller than theshells according to the aforementioned knee brace embodiment, they areoften located closer together, and proximate to the knee.

Particular benefits of the shells of the aforementioned embodiment arediscussed in the following examples. In these examples, it is assumedthat a force strap is provided which is pulled with a 10 N force, andthe width of the knee or distance x is the same. In the first instance,the distance Y, which is defined as the distance between the shells, is6 units. By moving the distance Y to 8 units, a greater moment due tothe leverage arm is formed by the distance of the shells. Because of theincrease in distance Y, the vertical force caused by the force strap isincreased as a result of the change in angle of the force strap.Consequently, the shells are more strongly urged towards one another. Onthe other hand, the horizontal force is reduced so that the pressure onthe knee in the horizontal direction is reduced, even though there is agreater moment applied to the knee.

It follows that if the shells are moved closer together, for exampleback to 6 units in distance, the moment is reduced yet there is morehorizontal pressure on the knee. Moreover, the force exerted by theforce strap must be increased in order to achieve the same amount ofmoment as created when the shells are separated by 8 units which resultsin yet more horizontal force about the knee. By providing the dual forcestrap arrangement, it is readily evident that the dual force strapprovides two points of pressure and two straps creating a load on theknee. Therefore, the knee brace is more comfortable when unloading aknee since there is greater pressure distribution.

In addition to the advantages of the shells regarding pressuredistribution, the shells can be arranged to extend over a greaterportion of the leg than in known frame members. For example, prior artbraces have small frame members that extend minimally about the leg, andthe frame members have a tendency to rotate about the knee when theforce straps are unloading the knee. This results in minimal tibiahyperextension and ligament control.

v. Sleeve

FIGS. 28 and 29 illustrate an embodiment of a sleeve 12 and the spacerelements 46, 48 that form proximal and distal pockets 84, 86therebetween. The pockets 84, 86 include proximal and distal openings74, 76. The openings 74, 76 may be closeable with closing means such ashook and loop fasteners, zippers, buttons, and other suitable means. Theopenings 74, 76 are configured for permitting insertion of the shells40, 42 into the pockets 84, 86 which are shaped to closely conform tothe shape of the respective shells 40, 42. The sleeve 12 further definesproximal and distal eyelets 78, 79, which correspond to the proximal anddistal eyelets 62, 63 of the shells 40, 42.

In a variation of the embodiment of FIGS. 28 and 29, the sleeve includespockets within the sleeve itself, wherein the shells are insertable intothe pockets, and the pockets are closeable with a suitable fastenerfeature, such as with hook and loop fasteners, stitching, rivets, andother known means readily available to a skilled artisan. The spacerelements are secured against a rear portion of the sleeve correspondingin shape and location to the shells.

In another variation, the sleeve and spacer elements may be secured toone another so that the pockets form at the lower side of the proximalsection and the upper side of the distal section. According to thisvariation, the shells may be inserted into the pockets so that thespacers and sleeve effectively cover the shells, yet so that the shellsare easily removed from the sleeve and spacers. This also enables theshells to slide into the pockets while the shells are still connected toone another.

In yet another variation, the shells may be secured, either permanentlyor removable, to the posterior side of the sleeve with a suitablefastener feature. In yet another variation, the brace may be providedwithout the sleeve, and simply possess the structure shown in FIG. 11,wherein the spacer elements are secured to the shells by a suitablefastener feature. A hinge may be used to connect the shells, or othersuitable connecting elements may be used to prevent the shells frombeing drawn towards one another when the brace is provided without thesleeve.

In yet another variation of the sleeve, the sleeve comprises proximaland distal portions that are separate from one another. According tothis variation, the proximal and distal portions may include theaforementioned pockets for retaining the shells, or in the alternative,the shells may be secured to a surface of the sleeve portions. Accordingto this variation, the sleeve portions may be connected by a hingelocated on one of the lateral or medial side of the brace, or with oneof the other connecting element described herein.

Another variation of the sleeve is shown in FIG. 30 wherein the sleeve242 is configured for enveloping frame elements and is removabletherefrom. According to this variation, the sleeve 242 generallyconforms to the outer surfaces of the proximal and distal members, andpreferably envelopes the outer surfaces of the aforementioned featuresof the knee brace. The sleeve 242 includes an opening 246 that generallycorresponds to an anterior knee. This provides access to the knee capand is located at a portion of the sleeve that is subjected to bendingof the knee.

Encircling the opening 244 is a first beveled portion 246 that eases theflexion of the sleeve 242 during gait. In addition, the sleeve 242 isprovided with a second beveled portion 248 disposed along the proximaland distal edges. The first and second beveled portions 246, 248 relievethe brace of any sharp or blunted edges that may catch on clothing, andare thus provided to facilitate the donning of clothing over brace.

The sleeve 242 may be applied over the underlying features of the kneebrace in a variety of manners. According to the variant shown herein,the sleeve 242 takes the form of a socket that surrounds the underlyingfeatures. Also, the sleeve 242 may include pockets wherein proximal anddistal shells may be inserted therein, and means on the exterior of thesleeve for securing spacer elements. The sleeve may be unrolled from arolled up condition for donning over the underlying features, and issecured thereon due to elasticity of the sleeve or, in the alternative,by hook and loop fasteners or other suitable means.

The sleeve 242 may include a zipper 290 located along one side of theproximal section thereof. As shown in FIG. 31, the zipper 290 providesan access 292 to a tightening mechanism 295 secured to a proximal shell293 and a force strap 294. This particular variation allows forconcealment of the tightening mechanism 295 under the sleeve 242, yetstill permits facile access for adjusting the tightening mechanism.Moreover, this variation prevents the tightening mechanism from catchingon clothing or any other objects that the leg may come into contactwith, and further provides for a more cosmetically pleasing brace. Theproximal portion of the sleeve can have a similar zipper and access tothe distal shell.

The sleeve may be constructed of a fabric including spandex, lycra,nylon, polyester, OUTLAST, COOLMAX, AEROSPACER, microfiber,three-dimensional fabrics, and other suitable fabrics. The sleeve mayhave various treatments incorporated therein such as antibacterial,scenting, and moisture wicking agents.

In yet another variation of the sleeve, the sleeve may be constructed asthe orthotic sleeve in U.S. Pat. No. 6,592,539 wherein elasticizedfabric is used to form the sleeve and is arranged in different sectionsthat exhibit different elastic stiffness in lengthwise and widthwisedirections of the fabric. That is, the fabric is essentially stiffer inone direction than in a direction perpendicular to the one direction.

vi. Spacers

As shown in FIGS. 11 and 29, the brace 10 includes proximal and distalspacer elements 46, 48 that are contoured in a similar configuration asthe shells 40, 42. These spacer elements 46, 48 are arranged so as to bebreathable by permitting a free flow of air therethrough. The spacerelements also preferably include a friction feature on at least one sidethereof.

The spacer elements may be connected to the sleeve via removable means,such as with a hook and loop fastener system, or may alternatively besecured to the sleeve via stitching, adhesives, or other similarfastener features. While the spacer elements are intended not tointerfere with the motion of the knee, they are intended to providesufficient frictional force to maintain the shells against the knee dueto the vertical forces created by the force straps.

According to this embodiment, the spacer elements 46, 48 are secured tothe posterior side of the sleeve 12. The spacer elements 46, 48 have abreathability feature 88. According to a variation, the breathabilityfeature comprises a pattern of openings defined across the spacerelements 46, 48. Alternatively, the breathability feature may comprise abreathable fabric, and may be combined with a pattern of perforations tofurther enhance the breathability of the spacers. Moreover, the spacerelements may be constructed from a material that provides cushioning andfurther compresses, at least in part, when the brace is worn.

As shown in FIG. 32, the spacer elements 46, 48 preferably have afriction feature 92 that is coated on at least a posterior surface of asubstrate material 90 that forms the body of the spacer elements 46, 48.This friction feature 92 has a high frictional coefficient against theskin or clothing. Moreover, the friction feature 92 does not occlude thebreathability feature 88 of each spacer element 46, 48, and permits atransfer of air through the spacer elements.

According to this embodiment, the spacer elements have a mesh or coreportion 94 that permits the passage of air therethrough, and yet iscompressible to provide adequate cushioning and securing to a leg whenplaced in tension. In addition, the spacer elements have a reinforcededging 96 provided to protect the core portion, and enhance thedurability of the spacer elements.

In another variation, as shown in FIG. 60, the spacer elements may bedirectly connected to the shells. Of course, such spacer elements may beconfigured so that they may be removed from the shells and reappliedwithout harming their structure. Fasteners such as hook and loop systemsmay be used to attach the spacer elements to the shells.

Preferred substrate materials that may be used to form the spacerelements include foams, neoprene, and textiles. While numerous materialsmay be used as the spacer elements, it is desirable that these materialshave a three-dimensional knit structure covered by a mesh that providessufficient breathability, insulation, compression, durability, andrecovery. An exemplary material is produced by Gehring Textiles underproduct numbers SHR 701, SHR 714 or SHR 754F.

According to this embodiment, the posterior surfaces of the spacerelements are coated with the friction feature which comprises acontinuous, discrete layer of cured silicone elastomer material 92. Thesilicone elastomer material is preferably sufficiently thick and soft tobe comfortable to the user, and yet provides a seal between the proximaland distal members, and the skin or clothing of a user of the brace 10.The silicone coating preferably has apertures which correspond toapertures of the mesh surface of the three-dimensional fabric when sucha fabric is used to form the substrate of the spacers. In a variation,the silicone coating may comprise a plurality of dots which aredeposited to the surface of the substrate of the spacers.

The silicone material may be mixed with scenting, anti-inflammatory,anti-bacterial, and coloring agents. Moreover, the silicone material mayinclude skin friendly agents such as aloe vera or Vaseline. A morecomplete description of additives to the silicone may be found in U.S.Pat. No. 6,485,776 assigned to Össur hf and incorporated herein byreference.

The silicone elastomer preferably has a Shore hardness of 25–70; aminimum tensile strength of 230 lbs/inch; a 100% modulus of 8 psi; a500% modulus of 61 psi; a minimum tear strength of 49 lbs/inch; amaximum strength of 500 lbs/inch and an elongation of about 1000%.

The silicone elastomer coating may be disposed in a uniform thickness inboth circumferential and longitudinal directions, or may have a varyingthickness to accommodate varying shapes of a leg, protrusions, contours,etc. The coating may also be configured to have a specific relief fromlocalized pressure that may result from installation of the proximal anddistal members on a human leg.

While the spacer elements are preferably coated only on their posteriorsurfaces, the anterior surfaces of the spacer elements may likewise becoated so as to frictionally couple with the sleeve. In the alternative,the friction elements may be constructed of sections of elasticizedfabric and coated with silicone of the type described in U.S. Pat. No.6,592,539.

In a variation of the brace, the brace does not include the spacerelements and instead relies on the proximal and distal member straps forattachment to a user. In another variation, the spacer elements that arenot coated with silicone. These spacer elements provide a compressivebuffer between the proximal and distal members and a leg of a user ofthe brace. In yet another variation, the substrate may comprise atextile having superior frictional properties, and as a result, merelythe compression of the textile is sufficient to prevent rotation of thebrace when worn on a leg.

In yet another variation, the spacer elements may comprise a siliconemesh comprising a textile that is impregnated with silicone. Thissilicone mesh defines a pattern of apertures that permit the transportof air therethrough. In yet another variation, the spacer elements forma silicone sheet having a pattern of apertures, and sufficient thicknessto serve as a buffer between the sleeve, frame members, and a leg.

vii. Tightening Device

Turning to another component of the brace, the brace includes atightening device 22, 23 that is provided for adjusting the tension ofthe force straps 18, 20. FIG. 33 schematically illustrates oneembodiment of the tightening device as a ratcheting system 98 thatpermits tightening and release of a cable 102 connected to the forcestraps 18, 20. An end of the force strap 20 is secured to a ring 100that is fixed to the cable 102. The tightening device 32 is configuredto incrementally provide or release tension to the cord 30.

According to this embodiment, the cable 102, ring 100 and end of theforce strap 20 are contained within the sleeve 12. It will be understoodthat in alternative embodiments, the cable, ring and force strap may beat least partially or completely outside the sleeve.

FIG. 34 illustrates an embodiment of a ratchet assembly 98 connected tothe cable 102 and ring 104. In this embodiment, the cable 102 departsfrom a ratchet body 106 through opening 116 and secures at one end to aseat defined on the ring 104. The ratchet assembly 98 includes arotatable handle 108 that is indexed to indicia 110 defined on the body106. A button 112 is slidable within slot 114 and permits release of theratchet assembly. According to this embodiment, the handle 108 rotatesas the cable 102 is unwound from the ratchet assembly 98.

The handle 108 provides mechanical leverage and provides independent useand adjustable security. The indicia 110 enables a user to measure andcontrol the degree of rotation of the handle 108, and thus determine theextent of the force applied on the knee by the force strap. The handle108 is pivotable so as to place the ratchet assembly 98 in a low profileconfiguration when the handle 108 is not in use.

The internal mechanism of the ratchet assembly 98 is shown in FIG. 35.In this embodiment, the housing 106 contains a ratchet wheel 126 havinga plurality of teeth, and a spool 127 which are mounted to rotatetogether on axle 128. A pawl 118 is mounted on axle 124, and has firstand second portions 120, 122 extending from the axle 124. The firstportion 120 connects to the button 112, and the second portion 122extends obliquely relative to the first portion 120 and engages teeth ofthe ratchet wheel 126.

FIG. 36 depicts another embodiment of the tightening device that may beused in the knee brace. According to this embodiment, a ladder strap 130has a buckle 138 which secures to an end of the strap 20. A lever 136 ispivotably secured to the shell 40 and engages one of numerous grooves134 of the ladder strap 130. The grooves 134 may be provided withindicia that correlate to a degree of tensioning of the strap 20 againstthe knee.

Preferably, the lever 136 is biased towards the ladder strap 130. Afirst end of the lever 136 engages one of the grooves 134 of the ladderstrap 130 and secures the ladder strap 130 from movement relative to theshell 40. Of course, if pressed at a second end opposite the first end,the lever 136 is released from one of the grooves 134 and the ladderstrap 130 may be adjusted relative to the lever 136 accordingly.

In this embodiment, the ladder strap 130 includes a grasping element 132in the form of a ring formed at an end opposite the connection to thestrap 20. As better exemplified in FIGS. 7 and 8, the grasping element132 is intended to extend outwardly from the sleeve 12 so as to provideaccess to a user of the brace. Moreover, the latch 136 may extendoutwardly from the sleeve 12 so as to facilitate adjustment of theladder strap 130 and to permit an indication as to which groove 132 thelatch 136 engages.

The ladder strap is preferably formed from a resilient material and mayflex to have a curvature that generally corresponds to a leg of a wearerof the brace. The grasping element is not limited to a ring, and may beformed or comprise a variety of known constructions that permit easyhandling for a user of the device. While the grooves of the ladder strapare shown as having a generally oval shape, it will be appreciated thatother shapes or configurations are possible such as saw tooth teeth,rectangular teeth, and symmetrically triangular teeth.

According to one variation, the latch has a protruding forward endoriented with a bias towards the groove of the ladder strap in order toimprove the latch's ability to positively engage one of the grooves ofthe ladder strap. The protruding forward end is preferably sized andconfigured to engage each of the grooves on the ladder strap.

The latch body may be pivotable between an engaged position wherein theforward end of the lever engages the grooves of the ladder strap, and areturn position wherein the forward end of the lever is slidable overthe grooves. In the engaged position, the protruding portion of theforward end of the latch functions as a pawl for the ladder strap. Aninternal biasing mechanism, such as a torsional spring, may be used tobias the protruding portion of the forward end towards the engagedposition. The lever may have portions that are cutout, which not onlylighten the lever by reducing the amount of material required, but alsoprovides access to the area underneath the lever.

According to a variation of the tightening device of FIG. 36, FIGS.37–40 illustrate a ladder strap compliant mechanism 500. In thismechanism, the latch 504 is resiliently biased towards the ladder strap502.

The latch 504 defines opposed arms 522 which form part of an upper mount512 that is secured to a lower mount 514 positioned on a base 506. Thearms 522 are sufficiently compliant to withstand torsion in the event arear end 526 is depressed to disengage a detent 516 located at a frontend 524 of the latch 504 from the teeth 510 of the strap 502.

The ladder strap 502 defines a grasping element 508 defined at a forwardend and a plurality of teeth 510 which permit incremental adjustment ofa force strap. The strap 502 also defines a rear end 520 that flares inwidth. The latch 504 is positioned relative to the strap 502 so that thelatch lies between the grasping element 508 and the rear end 520. Thisis so as to prevent the rear end 520 from passing through the latch 504and to establish a maximum distance that the grasping element 508 may bedrawn from the detent 516.

The base 506 is provided for mounting the latch 504 and for which thestrap 502 slides thereon. The base 506 includes apertures 518 formounting onto shells of the knee brace.

The tightening device 500 may be constructed from a variety of flexibleand resilient materials including plastics, metals and composites.Moreover, the strap 502, latch 504 and base 506 may be constructed fromdifferent materials.

In a variation of the base 506 according to FIGS. 37–40, FIGS. 41–43illustrate another base 528 having additional features to those of base506. According to this variation, the base 528 is integrally formed witharms 530 that in turn are integrally formed to the latch 529. As withthe embodiment of FIGS. 37–40, the latch 529 is resiliently biasedtowards the base 528, and includes detent 516.

The base 528 includes guard portions 534 that extend along the edges ofthe base 528 from the arms 530. These guard portions act to prevent aladder strap from shifting laterally with respect to the detent 516.

The latch 529 includes a dosage meter 532 that indicates the relativeposition of a ladder strap to the base 528. The latch may also includeindicia 537 that indicate a release button 536 which protrudes from thelatch 529.

The base 528 includes a compliant edge 531 provided about the peripherythereof. Methods for supporting methods for making the compliant edgeinclude those described in U.S. Pat. Nos. 5,445,602, 5,713,837 and6,024,712 which are incorporated herein by reference. The compliant edgeprovides conformity to the anatomy of a wearer of the brace in that theimpact of the edges of the base 528 are lessened against the wearer ofthe brace.

The compliant edges are relatively thinner than the base 528 andsubstantially more flexible than the material forming the base. Thecompliant edge is formed onto the base by being molded of plastic orother flexible material in a single molding step and secured together.Also, as indicated above, a compliant edge or edge portions may beprovided for the shells of the knee brace wherein the compliant edge oredge portions are provided about the periphery of the shells in order topermit the edges of the shells to conform better to the anatomy of thewearer of the brace.

The embodiment of the base according to FIGS. 41–43 also includes anarray of holes 533 that are arranged to receive a knob (as shown in FIG.42) for securing to the shells. Each of the holes 533 includes a rim 535that frictionally secures against the knob. The array of holes permitthe selection of placing the knob in one of the holes to effectivelylengthen or shorten the distance between connection to the shells andthe latch 528.

FIG. 44 illustrates the base 528 assembled with another embodiment of aladder strap 539. In this assembly, the knob 538 is secured within oneof the holes 533. The ladder strap 539 includes a plurality of indicia542 identifying the teeth 541 of the strap 539. The ladder strap 539also includes a plurality of apertures 543 located at an end oppositethe grasping element 545. The plurality of apertures 543 are arranged tosupport threads, rivets or other fastening means that secure a forcestrap thereto.

FIG. 45 illustrates the ratchet assembly of FIG. 44 secured to theproximal shell 422 of FIG. 22. In this embodiment, the knob 538 issecured to the rim 445 of the slot 444. The security of the knob 538with the slot 444, and hence the frame 422, allows for the tightening ofa force strap 546 that is connected to the ladder strap 539 which inturn is engaging the base 528 of the ratchet assembly. As shown, thebase 528 extends under the frame 422 so that the knob 538 can projectthrough the slot 444 and secure to the rim 445.

FIGS. 46–48 exemplify a ratchet assembly sharing some features with theratchet assembly of FIG. 44 and further includes a mounting system formaintaining the ladder strap 539 close to the base 528. In this example,the mounting system comprises a pin and slot system such that the ladderstrap 539 forms a pin 572 that extends through a slot 576 longitudinallyformed along the base 528. The pin 572 includes a flanged portion thatis sized larger than the slot 576 and is adapted to fit through opening578 disposed at a forward end of the slot.

The ladder strap 539 also includes a raised portion 574 with suitableapertures 582 for mounting to a force strap. This arrangement isadvantageous in that the strap may be mounted generally parallel withthe teeth 541 of the ladder strap 539 so as to align the forces andprovide greater stability.

The mounting system is particularly provided for assuring that theladder strap 539 remain in close proximity to the base 528 andfacilitate the ratcheting thereof. This is of particular benefit in theevent that the base is custom molded to conform to the leg of a patientwhen the ladder strap is not molded. Of course, this embodiment ismerely exemplary of a mounting system and other mounting systems mayalso be used to effectively stabilize the ladder strap relative to thebase, and hence the leg of a knee brace wearer.

FIG. 49 shows another variation of a tightening device that may use inthe knee brace of this application. According to this embodiment, theforce strap 20 is mounted outside the sleeve 12 or onto a frame member,and the force strap is secured to a bracket 146 at an end thereof whichis connected to a ladder-type strap 142. The ladder strap 142 defines aplurality of transverse teeth or protrusions 144. A latch 140 is mountedto the sleeve 12 or a frame member in a manner similar to the embodimentof FIG. 36, which engages the teeth 144. While this embodiment does notshow indicia for each position the strap is tightened relative to thesleeve 12, the teeth may be shortened and have a width that is less thanthe width of the ladder strap 142. Indicia may be provided alongsideeach tooth of the ladder strap.

According to yet another variation, loop material is secured onto astrap and hook material is secured onto a corresponding shell.Alternatively, a plurality of rings are provided on the shells throughwhich the force straps pass through. The force straps include hook andloop portions that correspond to one another and permit maintaining theforce straps in place.

Commercial examples of a tightening device that may also be used withdifferent embodiments of the knee brace include the BOA lacing system ofBOA Technology Inc. of Steamboat Springs, Colo., or in the alternative aratcheting buckle in combination with a ladder strap that is sold by M2Inc. of Winooski, Vt. under product name 1″ Mechanical Closure System(part numbers RB502 & LS 118-WB).

In any of the embodiments concerning the tightening device, it isintended that the tightening device provide precise adjustment, whetherincremental or not, of the force straps, and possess a sufficientlyrobust construction to withstand the tensile stress of the force straps.Different configurations of hook and loop fastener systems, buckles,straps, cords and ratchets are clearly envisioned as being used in thetightening device so as to provide simple adjustment and effectiveadjustment of the force straps.

viii. Strap Attachment Piece

An embodiment of a strap attachment piece 560 is shown in FIGS. 50–52.According to this embodiment, the piece 560 includes a generallytriangular body 562 having a knob 564 that is formed at a first end ofthe body 562. The knob 564 includes a tapered head portion 572 thatfacilitates securing the knob 564 onto one of the slots of the framemembers, for example slot 446 of FIG. 22.

A plurality of apertures 566 are defined between second and third endsof the body 562. Each of the apertures 566 includes a tapering portion568 beginning from the side of the body 562 including the knob 564 topreferably the opposed side of the body 562. The tapering portion 568eases the pressure exerted onto body 562 by stitching, rivets, pins orother suitable means useable for securing straps to the piece 560.

Referring back to the brace in FIGS. 7 and 8, the brace includes thebuckle assemblies 32, 33 that connect to the stability straps 28, 30. Itis preferred that the buckle assemblies 32, 33 generally have a lowprofile so that they do not protrude greatly from the sleeve. Moreover,the buckle assemblies should be relatively simple to use while having ananatomically conforming shape and providing sufficient leverage totightly secure the stability straps against the leg.

ix. Buckle Assembly

In an embodiment of the buckle assembly shown in FIGS. 53–55, a lowprofile buckle assembly is provided which locks the stability straps 28,30 in position relative to the shells 40, 42. This embodiment includesbracket 148 that secures to the strap 20 and connects to an arm 150having a forward end 152 slidably engaging a lever body 154. The arm 150extends through a clearance 160 defined by the lever element 154 and hasprotruding elements 158 that engage with edges of the lever body 154defining the clearance 160 that extends from a forward end 166 to arearward end 164 of the lever body 154. As a result of the constructionof the lever body 154, and its relationship to the arm 150, the arm 150is slidably connected to the lever body 154.

A base element 156 is pivotably connected to the rearward end 164 of thelever body 154. The base element 156 includes receiving holes 162 thatare configured to receive the protruding elements 158 of the arm 150,and a locking feature 158 for securing onto one of the shells 40, 42.According to this embodiment, the locking feature is a button bodyhaving a head portion 168 with a diameter greater than the rest of thebutton body. The head portion 168 is intended to have a diameter greaterthan the seat portion 64 of the eyelet 62 defined on the shells 40, 42.

The lever element 154 is pivotable between a disengaged position shownin FIG. 53 and an engaged position shown in FIG. 55. FIG. 54 shows anintermediate position between the disengaged and engaged positions. Inthe engaged position, the forward end 164 of the lever element 154 isbrought against surface 170 of the base element 156, and the arm 150rests upon the surface 170 with the protruding elements 158 engaged withthe receiving holes 162 of the base element 156.

Preferably, the protruding elements 158 are resiliently urged into thereceiving holes 162. In the disengaged position, the lever body 154 ispivoted away from the surface 170 of the base element and the protrudingelements 158 are removed from the receiving holes 162. The arm 150 maybe positioned between the forward end 166 and rearward end 164 of thelever body 154, and a pin (not shown) may be located at the connection.

The bracket 148 includes a ring 172 for the strap 20 to extend through.In this embodiment, the strap 20 has a hook and loop system permittingan end portion 174 of the strap 20 to secure to a receiving portion 176of the strap 20. A user may set an approximate desired length of thestrap using the hook and loop system prior to securing the buckleassembly. Subsequently, the buckle assembly is placed in the engagedposition so as to securely place and secure the knee brace on the leg.

The buckle assembly includes a curved profile such that it conforms tothe leg of a wearer of the brace. This imparts a more streamlined buckleassembly and further prevents buckle assembly from snagging on clothingor acting as an impediment to the wearer of the brace.

Another variation of a buckle assembly 188 is depicted in FIGS. 56–58.In this variation, the base element 193 and the bracket body 191 areconnected to one another, thereby reducing the amount of parts andsimplifying donning of the bracket and buckle to the shells.

As with other variations of the bracket assembly, the bracket body 191includes a clearance 192 arranged for receiving a strap. The buckleportion of the assembly 188 is similarly arranged as in the embodimentsof FIGS. 53–55 in that it includes common features such as the baseelement 189, lever body 190, arm 193, protruding element 197, andbracket 191 having the clearance 192.

The buckle assembly 188 has a securing feature located at the endportions of the base element 189 and the lever body 190. Specifically,the base element 189 carries a recess 199 upon which a hook 198 formedfrom the lever body 190 secures thereonto. The hook 198 is biased toextend into the recess 199 and urge against the base element 189. Thehook 198 is also resilient so that it can deflect when the lever body190 is urged away from the base element 189.

The buckle assembly 188 also includes a bracket 195 which is integrallyformed with the base element 193. The bracket 195 extends obliciuelyrelative to the base element 198. The bracket 195 includes a clearance196 that is arranged to receive a force strap. The buckle assembly 188has a curved profile that is similar to the curved profiles of thebuckle assembly of FIGS. 53–55.

In yet another variation of a buckle assembly depicted in FIG. 59, aclamping member 178 tightens the stability strap 179 to the brace 181.According to this variation, a second side 185 of the strap 179 issecured to one side of the brace 181, and a first side 183 of the strap179 secures to the clamping member 178. The clamping member 178 ispivotally connected to the brace 181, and is arranged to be biasedagainst an external surface 187 of the brace 181. The second side 185 ofthe strap 179 is detachable from the clamping member 178 and may besecured therewith with a hook and loop fastener system.

The buckle assembly may be constructed from plastic or a reinforcedcomposite. A plastic construction provides the sufficient resiliency forthe protruding elements to compliantly pass through the receiving holesof the base element. Moreover, the plastic buckle assembly reducesweight of the brace and has some compliancy against the leg of a user ofthe brace. It is possible to reinforce the buckle assembly with a carboncontent, such as a TRIAX based buckle assembly. Other examples ofcomposite based buckle assemblies include those constructed with delronor nylon having reinforcing carbon, KEVLAR or glass fibers.

It will be noted that the buckle assembly may also have parts that areconstructed from metal, such as an aluminum or titanium alloy. The metalparts provide superior strength and may be sufficiently lightweight. Insuch a metal based bracket assembly, the protruding elements may bemetal components having a resilient o-ring surrounding the protrudingelements that has sufficient compressive properties to be placed throughthe receiving holes of the base portion. Of course, in such anembodiment, the metal protruding parts preferably have a diameter lessthan the diameter of the receiving holes.

Variations of the aforementioned buckle assembly may be used to securethe stability strap to the brace. These variations include an embodimentwherein the strap is fastened to a buckle assembly with a rivet, and aring is provided on a side of the sleeve opposite the buckle assembly.The length of the strap may be simply adjusted with a hook and loopsystem provided on the strap.

In a variation of the buckle and tightening devices described above, thetightening devices may be secured to a buckle instead of being directlyconnected to the shells. This permits the buckle to control both ends ofthe straps.

In accordance with one method for donning the knee brace with theinventive buckle assembly, the method is performed in the followingsteps. First, one force strap is attached to a corresponding buckleassembly, thus requiring only one connection as opposed to two. Next,during an initial fitting, the buckle assembly is connected to the shelland subsequently locked. The leg of the wearer is extended and the forcestrap is then adjusted such that the force strap is adjustable inlength. This results in removing the need to adjust the length of theforce strap upon each donning unless the leg changes in size, or forsome other reason. The stability strap corresponding to the buckleassembly is also tightened accordingly. Both buckle assemblies areconnected to the shells, and the remaining unsecured force straps andstability straps are tightened.

Unloading of the knee is conducted with the wearer flexing the knee bybending it, and by tensioning the force strap with correspondingtightening devices. After the wearer is finished with wearing the kneebrace, the force strap is released and the buckle assembly is opened.The buckle assembly is then removed from the shells, and the brace issubsequently removed.

Upon repeated use, there is no need to adjust the stability straps, andthe force straps other than by the tightening device to unload the knee;all of the stability straps and force straps are already configured.Alternatively, a wearer may simply release the tension of the forcestraps, unbuckle the buckle assembly, and slide the knee brace off ofthe leg. In either way, the arrangement provides for simple donning ofthe knee brace onto a leg, and expedites securing and removal of theknee brace.

x. Hinge

In another feature of the knee brace, FIG. 60 schematically shows abrace 250 having a hinge 252 in combination with a force strap system256 of any of the aforementioned embodiments. The hinge 252 extendsbetween frame members 254, and is located opposite the intersection 258of the force strap system on the same side as the affected compartmentof the knee.

Preferably, the hinge 252 has flexion and extension stopping features tocontrol hyperextension and anterior drawer of the tibia. The hinge mayhave an adjustment mechanism that enables a user or clinician to adjustthe varus/valgus angle of the hinge.

One variation a hinge 260 for use in the brace of FIG. 60 is shown inFIG. 61. This hinge 260 is generally constructed from plastic orreinforced composite so as to be lightweight and have a generally lowprofile. The hinge 260 includes flexible brackets 262 that are providedfor connecting to the frame members 254. A first end of the proximal anddistal arms 264, 266 connect to corresponding brackets 262. A second endof these arms 264, 266 define a head 268, 270 having a generallycircular gear portion 272, 274. The heads 268, 270 are pivotably mountedabout axles 276, 278 of a housing 280 such that the gear portions 272,274 mesh with one another.

Each head 268, 270 is provided with first and second stop structures282, 286. The first stop structures 282 are located on an anterior sideof the hinge 260 and are arranged to contact a side surface 284 of thehousing 280 in order to limit rotation of the hinge 260 in the anteriordirection of the brace. The second stop structures 286 of the head areformed on a generally posterior side of the hinge, and are arranged tolimit rotation in the posterior direction of the brace.

Apertures 288 may be formed in the housing 280 along the path of thestop structures as the heads 268, 270 rotate. These apertures areadapted to receive a screw or pin. The screw or pin is provided to blockor engage one of the first and second stop structures to further limitrotation of the hinge.

In a variation of the hinge, FIG. 62 shows a hinge 301 having adifferent arm construction from the construction of hinge 260. Accordingto this variation, the arms 303, 305 are integrally formed withcorresponding heads 315, 317. In addition, each of the arms 303, 305 iscontoured to accommodate or correspond to the shape of the distal andproximal shells of the knee brace.

FIG. 60 shows the hinge 301 connected to proximal and distal shells 309,311. In this variation, the hinge 301 includes a face plate 319 thatcovers the heads 315, 317. The arms 303, 305 are bent to generallyanatomically accommodate a leg. Also, the arms 303, 305 are secured torespective shells via pins or buttons 313.

The hinge 301 may be releasably securable to the shells 309 and 311 inFIG. 61. The buttons 313 are configured to be insertable into theopenings 321 and locked in a slotted portion (not shown) that is similarto the slots 445 in the flame 422 of FIG. 45, or other frame slotsdescribed herein.

According to other variations, the removable hinge may be secured to theshells with a series of corresponding snap fasteners, or other suitablefastener devices. The shells may be particularly configured to includeapertures that can receive self-piercing fasteners. The removable hingeenables wearers to use the hinge for intense leg activity and greaterstability, and remove the hinge for more normal use, greater comfort,and a more streamlined brace.

The hinge controls the motion and angular displacement of the brace forstabilization and control of the knee joint. Preferably, the hinge has athin profile, and is constructed of a lightweight material such asplastic, composite materials, or metals. Unlike other hinges, this hingedoes not include an adjustment mechanism since as soon as the forcestrap system 256 draws the knee against the hinge, the hinge woulddeflect away from the knee due to its flexibility.

Other hinge types may be employed such as those described in U.S. Pat.No. 5,277,698 currently assigned to Generation II USA, Corp. of Bothell,Wash., or in the alternative with a anatomically orthopedic hingedescribed in U.S. Patent Application Publications 2004/0002674 A1 and2004/0054311 A1 assigned to Generation II USA, Corp. of Bothell, Wash.This patent and these application publications are incorporated hereinby reference.

Another embodiment of the knee brace 330 is shown in FIG. 63 that isconfigured for stabilizing both medial and lateral sides of the knee.According to this embodiment, force straps 332, 334 are configured toextend about opposite sides of the brace 330. Each of these straps 332,334 connects to frame members 336 that may comprise any of theaforementioned variations discussed herein.

In this embodiment, the force straps 332, 334 are provided to applyequal pressure on both sides of the knee. Depending on theconfiguration, one force strap extends along a proximal, lateral side ofthe knee whereas the other force strap extends along a distal, medialside of the knee. This embodiment is particularly useful for treatingligament injuries or infirmities due to the stability it provides forthe knee.

A hinge or opposed hinges 340, 342, such as the type of hinges discussedin connection with FIGS. 61 and 62, may also be employed to furtherstabilize the knee with this embodiment.

xi. Alternate Knee Brace Embodiment

FIG. 64 illustrates another embodiment of a knee brace 210 in accordancewith the present invention. This brace 210 includes a proximal framemember 212 and a distal frame member 214 both located on the anteriorside of the device 210, and extending between lateral and medialportions thereof. Both the frame members 212, 214 have anterior andposterior facing surfaces. A connecting element 216 connects the framemembers 212, 214. A force strap 218 is connected to the frame members212, 214, and defines first and second strap portions 220, 222 thatcross at an intersection area 224 located between the frame members 212,214.

The intersection area 224 is generally defined in the same region as inthe intersection area in the embodiment of FIGS. 7–10. Moreover, thelocation of the force strap 218 relative to the frame members 212, 214is similar to that also described in connection with the embodiment ofFIGS. 7–10.

A first end of the first strap portion 220 is anchored to the proximalframe member 212 and spirals towards the distal frame member 214. Aplurality of strap guides 226 guide the force strap 218 along an outersurface of the distal member 214 and redirect the force strap 218towards the proximal member 212. The second strap portion 222 emergesfrom the distal member 214 and intersects with the first strap portion220 while extending towards the proximal member 212.

A second end of the second strap portion 222 is secured to a bracket 228connected to a cord 230. The cord 230 is received by a tightening device232, of any of the types described herein that are secured to theproximal member 212. The tightening device 232, as described inconnection with the aforementioned embodiments, is provided toincrementally tension the force strap 218 and selectively allow releaseof tension in the force strap 218. The connection between the secondstrap portion 222 and the tightening device 232 is oriented in apredetermined direction to obtain a preferred orientation at theintersection area 224 between the first and second strap portions 220,222.

Proximal and distal spacers 234, 236 are connected to the frame members212, 214, respectively, along the inner surfaces thereof. As with theaforementioned spacers, the spacers 234, 236 have a coating that has ahigh frictional coefficient against skin or clothing. When appliedagainst skin or clothing, the friction spacers 234, 236 resist movementof the knee brace 10 relative to the skin or clothing.

The proximal member 212 includes a stability strap 238 secured andextending between opposed lateral and medial sides of the proximalmember 212. The distal member 214 includes a stability strap 240likewise secured and extending between opposed lateral and medial sidesof the distal member 214. The proximal and distal straps 238, 240preferably have hook and loop fastener systems to connect to the medialand lateral sides of the respective frame members 212, 214.

According to the embodiment of FIG. 64, the frame members 212, 214 maybe rigid or flexible members. Moreover, they may be perforated orrendered breathable in the manner described in reference to the shellsof FIGS. 18 and 19. In variations of the knee brace, however, the framemembers may be constructed of soft members that are sufficiently strongto withstand forces on a knee produced by the force strap 218 butsufficiently compliant to provide comfort to a user of the knee brace.

The connecting element 216 is a ring that connects to both the proximaland distal members 212, 214. The connecting element 216 is not limitedto a ring-like structure, and instead may be provided in any shapehaving suitable structure and strength that is sufficient to maintainthe frame members 212, 214 apart while providing sufficient bending overthe knee cap during gait.

The connecting element is preferably constructed of a medial gradesilicone having a sufficient durometer (i.e., 10) and sufficientstiffness to maintain the frame members 212, 214 apart. Alternatively,the connecting element 216 may be constructed of a stiff foam from EVA,plastezote or polyurethane.

In a variation at least one hinge provided on one of the medial orlateral sides of the brace may take the place of the connecting element,or be provided in combination with the connecting element.

The tightening device 232 may include any one of the aforementionedsystems used for tightening the force strap 218. Moreover, the forcestrap 218 and the stability straps 232 may be mounted onto the shells inany of the aforementioned manners described in connection with theembodiment of FIGS. 7–10.

xii. Additional Features

Additional features may be used in connection with the aforementionedembodiments of the knee brace.

One such feature includes load cells that are connected to force strapsto measure the force exerted on a knee. According to this feature, loadcells are connected to the first and second force straps. These loadcells monitor the pressure applied on a knee and relay via connections apressure reading to the tightening device. The tightening deviceaccording to this embodiment, is equipped with a drive motor (not shown)that incrementally adjusts the tightening device by either tightening orreleasing the force straps.

Of course, this embodiment is not limited to requiring two load cells,and one or multiple load cells may be used to determine the pressure onthe knee caused by the force strap.

This feature of the tightening device is particularly advantageous sinceit permits precise tension adjustment of the strap to treat a specificuser. The predetermined parameters include a range of dosagerequirements for users. These dosage requirements include forcesrequired for a user to unload the compartmental osteoarthritis of theknee. For example, one dosage would equal about 3 Nm of unloading. Themaximum unloading, in this example, is 12 Nm so 4 doses would provide amaximum unloading of the knee. The load cells may be configured for auser during a fitting process by an orthotist who could establish adosage requirement for the user.

In another variation, the load cells may be integrated with the kneebrace and the tightening device. The data obtained by the load cells canthen be used by the tightening device to change the tension in thecross-strap during a gait cycle. According to this variation, anaccelerometer device is required to determine the stage of the gait at aparticular point in time. This can be particularly useful when walkingup or down ramps or hills, or going up or down stairs since the knee isbears weight when in flexion so that the strap is pulled tighter duringsuch stages of walking.

In another feature that may be used in combination with embodiments ofthe knee brace, an inflatable bladder system for providing additionalcushioning and fitting of the force straps and stability straps. Asillustrated, the force straps are provided with a plurality of bladdersconnected to pump to provide relief to a leg. The bladders areparticularly positioned on the force straps at locations proximal anddistal of the leg whereat the force straps apply the maximum pressure onthe knee.

In operation, the force straps are applied over the knee with slighttension. As the bladders are inflated, the force straps tighten over theknee due to the increase in size of the bladders. The pump permitsinflation and deflation of the bladders. The pump may be integrated withthe force straps or be located remote therefrom.

Examples of pump and bladder systems that may be used in combinationwith the cross-strap of the knee brace are described in U.S. Pat. Nos.5,022,109 and 6,598,250 assigned to Dielectrics Industries of Chicopee,Mass., which are incorporated herein by reference.

The various embodiments of knee braces described above in accordancewith present invention thus provide a product that reduces pain, speedsa healing process, and imparts improved stability to the knee. The kneebrace is lightweight and has a streamlined profile that is simple to usefor wearers of the brace of various age groups. Moreover, the knee bracepermits more precise adjustment of the brace and enables efficientcoordination between a medical professional and the wearer as to thedegree the knee brace should be configured. Patient comfort is alsoenhanced, and donning and doffing of the brace is eased with the novelfeatures of the present knee brace.

Of course, it is to be understood that not necessarily all such objectsor advantages may be achieved in accordance with any particularembodiment of the invention. Thus, for example, those skilled in the artwill recognize that the invention may be embodied or carried out in amanner that achieves or optimizes one advantage or group of advantagesas taught herein without necessarily achieving other objects oradvantages as may be taught or suggested herein.

The skilled artisan will recognize the interchangeability of variousfeatures from different embodiments. In addition to the variationsdescribed herein, other known equivalents for each feature can be mixedand matched by one of ordinary skill in this art to construct a kneebrace in accordance with principles of the present invention.

Although this invention has been disclosed in the context of certainpreferred embodiments and examples, it therefore will be understood bythose skilled in the art that the present invention extends beyond thespecifically disclosed embodiments to other alternative embodimentsand/or uses of the invention and obvious modifications and equivalentsthereof. Thus, it is intended that the scope of the present inventionherein disclosed should not be limited by the particular disclosedembodiments described above, but should be determined only by a fairreading of the claims that follow.

1. An orthotic device divided into anterior and posterior sides by a frontal plane, and having first and second sides divided by a median plane, comprising: a resilient proximal shell having an outwardly facing surface; a resilient distal shell connected to the proximal shell and having an outwardly facing surface; a first force strap adjustable in length and having a first end directly attached to the first side of the proximal shell and a second end attached to the first side of the distal shell, the first force strap spiraling from the first side of the proximal shell to the first side of the distal shell about the posterior and anterior sides of the orthotic device the first force strap extending over a portion of the outwardly facing surface of the distal shell; and a second force strap adjustable in length and having a first end directly attached to the first side of the proximal shell and a second end attached to the first side of the distal shell, the second force strap spiraling from the first side of the distal shell to the first side of the proximal shell about the posterior and anterior sides of the orthotic device the second force strap extending over a portion of the outwardly facing surface of the proximal shell; wherein the first and second force straps intersect at an intersection point located on the posterior side of the orthotic device between the proximal and distal shells.
 2. The orthotic device according to claim 1, wherein the intersection point is defined at a location posterior of the frontal plane of the brace device at a location greater than 0° and at or less than 45° posterior of the frontal plane of the device.
 3. The orthotic device according to claim 1, wherein the proximal and distal shells are connected to one another with a hinge located on one of the first and second sides opposite the location of the intersection point.
 4. The orthotic device according to claim 1, wherein the first and second force straps are substantially inelastic.
 5. The orthotic device according to claim 1, wherein the first and second force straps each include a substantially compressible core and a textile-based outer layer surrounding the compressible core.
 6. The orthotic device according to claim 1, wherein a clearance separates the proximal and distal shells on both the first and second sides of the device.
 7. The orthotic device according to claim 1, wherein the first force strap is adjustably secured to the proximal shell and releasably secured to the distal shell.
 8. The orthotic device according to claim 1, further comprising a hinge having rigid proximal and distal arms connecting to the proximal and distal shells, respectively.
 9. The orthotic device according to claim 8 wherein the first and second force straps are attached to the proximal shell above the proximal arm of the hinge.
 10. An orthotic device divided into anterior and posterior halves by a frontal plane, divided into proximal and distal halves by a transverse plane, divided into first and second sides by a median plane, comprising: a proximal shell having an outwardly facing surface; a distal shell connected to the proximal shell and having an outwardly facing surface; and at least one force strap adjustable in length and directly connected to the proximal and distal shells, the at least one force strap having first and second portions intersecting at an intersection point located between the proximal and distal shells; wherein the intersection point is defined at a location posterior of the frontal plane of the brace; wherein at least one force strap is connected to the first side of the proximal and distal shells so as to extend without intersecting along the transverse plane on the second side of the device and to extend over a portion of the outwardly facing surfaces of the proximal and distal shells; wherein the at least one force strap has first and second ends, the first and second ends being connected separately to the proximal and distal shells.
 11. The orthotic device according to claim 10, wherein the at least one force strap is substantially inelastic.
 12. The orthotic device according to claim 10, wherein the at least one force strap includes a substantially compressible core and a textile-based outer layer surrounding the compressible core.
 13. The orthotic device according to claim 10, wherein the proximal shell extends between the first and second sides along the anterior side of the device.
 14. A method for securing a knee brace on a knee of a leg, the method comprising the steps of: applying a brace having at least one resilient shell around and against the knee such that first proximal and distal principal points of force are generated by at least one force strap of the brace on a first side of a median plane dividing the leg both above and below a transverse plane dividing the knee, respectively, as the knee moves to extension, and second proximal and distal principal points of force are generated by the brace on a second side of the median plane dividing the leg at locations above and below, respectively, the first proximal and distal principal points of force; wherein an intersection point is defined at a location posterior of the frontal plane of the brace; wherein the at least one force strap urges the at least one shell to generally conform to anatomy of the leg; wherein the at least one force strap extends over a portion of the at least one shell.
 15. The method according to claim 14, further comprising the steps of: coupling the at least one force strap to a proximal shell located above the knee; spirally wrapping the at least one force strap around the knee so as to extend in a first orientation towards a distal shell located below the knee; extending the at least one force strap about the distal shell; spirally wrapping the at least one force strap around the knee from the distal shell in a second direction towards the first rigid limb; and coupling the at least one force strap to the proximal shell.
 16. The method according to claim 14, further comprising the steps of: coupling a first end of a first force strap to a proximal shell located above the knee; spirally wrapping the first force strap around the knee so as to extend in a first orientation towards a distal shell located below the knee; coupling a second end of the first force strap to the distal shell; coupling a first end of a second force strap to the proximal shell; spirally wrapping the second force strap around the knee so as to extend in a second orientation towards the distal shell; and coupling a second end of the second force strap to the distal shell.
 17. The method according to claim 14, wherein the brace is applied such that the point at which the at least two principal forces are applied and the normal axis of rotation of the knee define at least two planes that are generally perpendicular to the longitudinal axis of the femur of a leg when the leg is extended.
 18. An orthotic device divided into anterior and posterior sides by a frontal plane, divided into proximal and distal sides by a transverse plane, divided into first and second sides by a median plane, comprising: a proximal shell; a distal shell connected to the proximal shell; a hinge having proximal and distal antis connecting to the proximal and distal shells, respectively; a first tensioning device adjustable in length and having a first portion received by and releasably attached to the first side of the proximal shell generally on the anterior side thereof and a second portion directly connected to the first side of the distal shell generally near the frontal plane of the brace, the first tensioning member spiraling from the proximal shell about the second side to the distal shell; and a second tensioning device having a first portion directly connected to the first side of the proximal shell generally near the frontal plane of the brace, and a second portion received by and releasably attached to the first side of the distal shell generally on the anterior side thereof, the second tensioning spiraling from the proximal shell about the second side to the distal shell; wherein the first tensioning device and the second tensioning device do not directly intersect at the intersection of the frontal and transverse planes on the second side of the device.
 19. The orthotic device according to claim 18, wherein the first tensioning device is freely adjustable relative to the second tensioning device.
 20. The orthotic device according to claim 18, wherein the first portion of the first tensioning device is received by the proximal shell at the location between the median plane of the brace and a position where the second tensioning shell is secured to the proximal shell. 